Science Interviews

Interview

Tue, 11th Feb 2014

The costs of keeping it cool

Graeme Maidment, London South Bank University

Listen Now    Download as mp3 from the show Green Food

Chris -   Now, we’ve heard from David Cebon the gauntletA fridge being thrown down there.  We need doors on fridges.  They waste an enormous amount of energy.  In fact, some stats we’ve seen suggest that refrigeration is a bigger environmental issue than transporting food around the country and around the world in the first place.  Graeme Maidment is professor of air and refrigeration at London South Bank University and he’s with us to give his perspective.  Hello, Graeme.

Graeme -   Hello, Chris.

Chris -   So first of all, what do you think of the comments that David is making about the fact that you go into a store and there's all these arrays of beautiful fridges full of products and they're all open?

Graeme -   Well firstly,  the comment I’d just like to come back on is the carbon emissions associated with refrigeration and air conditioning around the world.  We’re a very intensive industry.  We do a lot of things for the society, producing lots of cooling for lots of applications.  And as a result, we use lots of energy and produce lots of carbon dioxide.  I think you quoted it like double that of air traffic.  We produced about 10% of all carbon emissions worldwide.  

Supermarkets are energy intensive.  There's about 7,000 in the UK and they produce or they use something like 3% of all UK electricity.  Much of that is for refrigeration.  Now, something like 30% to 50% of all the energy that goes into a supermarket goes into the fridge and David is right.  At the same time, that cold leaks out into the store and has to be offset with additional heating.  So, supermarkets, they use lots of the energy and there's lots of them.  In terms of the design of fridges, fridges have been around for many, many years. The issue of doors on cabinets has come up over the last 3 or 4 years and a number of supermarkets are using doors on cabinets.  But there's other things that we can do as well to reduce our emissions.

Chris -    I tell you what, I've found some things that have evolved in my fridge as well, but that's a different story.  Is it just because there's this perception that if you put a door on a fridge, people won’t buy things?

Graeme -   I think there is some psychology associated with retail and I think anything that you put a barrier in its place or you don't display in the right way, so you don't get the lighting levels in the right way, it creates a potential marketing barrier.  So, I think retail is all about people seeing something and buying it impulsively.

Chris -   But these numbers that you've put on this are so staggeringly high that this suggests that we need some kind of policy, not just in Britain, but across the entire world to stop people doing what I would regard as flagrantly wasting energy.  Because if everyone has to put a door on their fridges, then no one is at a disadvantage relative to their competitors, are they?  And then the motivation and the impact is on people to develop fridges that people do want to open the door of and buy their contents anyway.

Graeme -   Yeah, I mean, doors on fridges are a good thing, but there's other things that we need to do.  We don't just need to hang on to a door on a fridge because if the carcass of the fridge and the components within it are the worst around then putting a door in it won’t do anything.  If you think about your home, if you fit double glazed and leave the front door open...

Chris -   What's the point?  Indeed.

Graeme -   The double glazing doesn’t have an impact.  So, there's lots of things that we need to do and there's lots of things that the industry in the UK are doing.  But there's others things we can do in terms of the storage practice.  I often go into the supermarket.  I see chilled naan bread and fresh pasta in the fridge.  Well, what was all that about?  Why aren’t we buying the pasta from the dried pasta or the unchilled naan bread or wine?  Why do we buy chilled wine? So, there's lots of practices that we have to change I think to actually reduce our need for cooling in the first place.

Chris -   Can we get to a point that you were making though which is about the fridge itself?  So, irrespective of whether the door is left open or not.  What we put in the fridges has caused a lot of scientific controversy over years.  Not just the food, I mean, the refrigerants, the chemicals that make the fridge do its job because we had a huge hole in the ozone layer, owing to the fact that we were putting chemicals in these fridges that we’re very good at keeping fridges cold, but they were very bad for the environment.

Graeme -   Yeah, ozone depletion was discovered in 1970s and the Montreal protocol was put in place to ban CFCs and the ozone layer has now recovered.  But the granddaughter of CFCs we found is a potent greenhouse gas so far.  It’s called HFC, hydroflourocarbon and these are refrigerants that we’re stealing away from now.

Chris -   So, in other words, by replacing CFCs with something that we thought would be better for the ozone layer, it’s just an environmental insult in a different direction.

Graeme -   Well, it’s had a different environmental impact and at that time, clearly didn’t know, but it’s come to pass now that the HFC refrigerants have got a high greenhouse effect.  So now, our industry is moving away from these, back towards some natural refrigerants and the sort of refrigerants that we use of things like carbon dioxide which is a greenhouse gas, but has got very low greenhouse gas potential – ammonia, hydrocarbons and things, a lot of those.  But all these refrigerants have got their challenges, which is why they stop using them many years ago.

Chris -   Well Graeme, I'm relieved that someone like you is on the case, if not just the fridge case.  Thank you very much.

Graeme -   Thank you.

Chris -   That's Graeme Maidment.  He’s from London’s South Bank University.  

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